This invention relates to vehicle seats that have varied levels of firmness, especially vehicle seats with a saddle-type construction.
Vehicle seats with a saddle-type construction are commonly found on vehicles that require a rider to sit astride for balancing purposes, such as motorcycles, snowmobiles, and water jet propulsion units. Saddle-type vehicle seats typically have a construction that includes a hard bottom plate made of metal or hard plastic, a stuffing cushion made of expanded urethane, and a seat skin made of synthetic leather. The firmness or rigidity of the seat when a rider sits on it is altered by changing the thickness of the seat skin or by changing the material or density of the cushion stuffing.
The inherent design of a straddle-type seat makes the seat conducive to permanent deformation caused by repeated sitting in a commonly-used seat position. Over time, the commonly-used seat portion recedes and takes a permanent set. This permanent deformation of the seat causes riding discomfort and may cause the rider's line of vision to be at an unsafe altitude for operating the vehicle.
In the past, receding and deformation of the seat was corrected by increasing the entire seat firmness. The entire seat firmness could be increased by using a thicker seat skin stretched over the entire seat surface or changing the material or density of the cushion stuffing. Increasing the entire seat firmness improved comfort in a rider's less sensitive buttocks region but impaired comfort in the sensitive thigh and coccyx region, small bone at end of spine. Additionally, stretching the uniformly thick seat skin over the entire seat surface tended to produce wrinkles and affect the seat appearance.
The object of the present invention is to provide a saddle-type seat with a greater firmness portion that eliminates the disadvantages of permanent deformation found in conventional seats.
Another object of the present invention is to improve sitting comfort by providing greater firmness in the buttocks region of a rider and less firmness in the thigh and coccyx region of a rider.
A further object is to provide a seat skin that can be stretched over the entire seat surface and maintain a nice appearance without wrinkles.
Further objects and advantages of the present invention will become apparent from a consideration of the drawings and ensuing description.